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SiriusHardware · 1st Oct 2021, 9:41 pm

Yes, I think there was a particular 877 port she wanted to use for the databus hence a very late change to the assignment of ports. It coincided with her decision to use the 877 instead of the 887, so, worst case scenario, there may be reason to change it back to the original wiring but still take into account that one of the page select pins also has to operate in a dual mode.

Another possibility is to (reluctantly) change to the PLCC packaged version of the 877 / 877A because that gets you a couple of extra port pins - but they can only realistically be used on a PCB, trying to hand-build without a PCB or at least a pin breakout board would be tedious in the extreme.

I do have some '44 pin PIC Demo' PCBs of the type which originally came with the Pickit 3 - we bought a number of those at work but we only really needed the programmers so the boards were up for grabs so I grabbed them. They typically came with PIC16F877 (QFP) versions fitted although they will accept QFP versions of the PIC16F877A, PIC16F887, PIC18F452 etc - but they are fine pitch devices which have to be soldered, of course.

1st Oct 2021, 9:41 pm	#524
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,577	Re: Ortonview PCB Yes, I think there was a particular 877 port she wanted to use for the databus hence a very late change to the assignment of ports. It coincided with her decision to use the 877 instead of the 887, so, worst case scenario, there may be reason to change it back to the original wiring but still take into account that one of the page select pins also has to operate in a dual mode. Another possibility is to (reluctantly) change to the PLCC packaged version of the 877 / 877A because that gets you a couple of extra port pins - but they can only realistically be used on a PCB, trying to hand-build without a PCB or at least a pin breakout board would be tedious in the extreme. I do have some '44 pin PIC Demo' PCBs of the type which originally came with the Pickit 3 - we bought a number of those at work but we only really needed the programmers so the boards were up for grabs so I grabbed them. They typically came with PIC16F877 (QFP) versions fitted although they will accept QFP versions of the PIC16F877A, PIC16F887, PIC18F452 etc - but they are fine pitch devices which have to be soldered, of course.